This application encompasses those activities required to complete development of a Decision Support System for Youth Well-Being (DSS-YWB), a web-based application designed to help meet the needs of those who manage programs that influence the prevalence of healthy and harmful adolescent behaviors. The Phase I prototype DSS-YWB is based on the concept of a feedback loop with four components, each of which is related to user decisions. These system components- Plan, Implement, Measure, and Compare - serve as an organizing framework for presenting tools that enable users to make, document, and defend decisions critical to incorporating efficacious practices in educational and other service settings. The goal for Phase II is to modify and expand these components to produce a commercial version of the program. Existing evaluations of the Phase I prototype, research on factors related to positive outcomes for youth, and analyses of barriers to the adoption, implementation, and maintenance of effective practices will be used to drive system modification activities. Initial evaluation will involve focus group and in-house testing of an Alpha revision of the program. The results of Alpha testing, coupled with reviews of the program by project consultants, will lead to the development of a Beta version, which will be evaluated using three concurrent replications of a four-group multiple-baseline design across human service decision-making groups in 12 Oregon counties. In each replication, the Beta version will be introduced to one group at a time and its impact will be compared to those groups not yet exposed to the program. We will compare assessments of the methods employed to (a) identify target behaviors, (b) select relevant interventions, (c) set goals for change, and (d) measure the effect of interventions. The resulting system, which integrates all of the tools required to assist decision makers in adopting, implementing, maintaining, and monitoring effective interventions, should prove to be highly useful to those charged with expending public resources to increase youth well-being.